Gripper brake for railways



12 1929- H. PCSENTRUP 1,714,621

.GRIPPER BRAKE FOR RAILWAYS Filed Feb. 11, 1925 Flg. L

I I u Patented May 28, 1929.

U ITE GRIPIPER BRAKE FOR RAILW'AYS.

Application filed February 11, 1925, Serial No.8,515, anrlin Germany February 19, 1924.

My invention is illustrated diagraminati cally and by way of example in the accompanying drawings, in which Fig. 1 is a longitudinal section through one of the con- 5 structional forms in which my invention may becmbodied, Fig. 1 and Fig. 1 being dia grammatic sections through the. braking mechanism and the wheel to he braked thereby. Fig. 1 showing the wheel in engagement with the brake and Fig. 1 showing the wheel out of engagement with the brake, Fig. 2 is va cross-section of Fig. 1, the movable parts being shown in their working position, Fig. 3 shows said movable parts in position of rest and Fig. i is a section in the plane fig-A of v Fig. 3. i p

This invention relates to a gripper-brake for railways having brake-rails which may be raised and lowered. It is known that railway vehicles may be braked by pressing a pair of brake-rails or the like with a relatively great force against the tyres of the wheels. A strong braking action can in this case be obtained, if, for instance, a wedge is-pressed into a wedge-shaped opening or if a wedgeshaped opening is pressed around a wedge. If, for instance, a member 1 as shown in Fig. 1 is pressed by means of a force R which acts in upward direction with its wedgeshaped opening against a wedge-shaped body having a weight R, the wedge-shapedbody s supported a counter-plate pertalnmg to one of the gripper-members f and g In Fig. 2

will. be lifted from its supporting member, for instance a rail, and a braking force Dwill be generated in horizontal direction, said fore-e D depending uponthe weight R and of the angle of the wedge. The braking forces will bee omeinetfectiv as soon as the member lis lowered to the extent shown in Fig. 1 The action of the present gripperbrake for railways is based upon the operations as diagrammatical indicated in Figs. 1 and 1".

The lifting wheels causing the lifting and lowering of the brake rails have been fully de scribed in my 'copending application for patent application Serial No. 4,073. According to this, for instance, a bridge-shaped construction which carries the slides and the brake rails is mounted upon rollers r as shown in Fig. 1 in such a manner that the entire construction may be moved forwardly and back wardly in the direction of the railway track by means of the force K as also indicated in Fig. 1. This force K may be furnished by an electric motor or pressure cylinder orthe like which is not indicated in the drawing.

indicated by dotted lines on the lefthand side of Fig. 1. In this case the railway vehicles may move without impediment through the brake along the track, while in lifted position of the brake each wheel of the vehicle which moves from the right-hand side to the left-hand side will be lifted and braked thereby. If the brake is lifted so as to act against the load of the railway vehicle, a braking action will take place tending to move the brake-rails together withthe entire braking mechanism towards theright-hand side. On the other hand the vertical. load of the vehicletends to move thebrake downwardly upon the inclined surfaces of the sup:

porting members 25 that is'to'say, the brake will be moved towardsthe left-hand side. These'two forces will approximately counter-- not each' other andthe brake may therefore be lifted and lowered with only a small expenditure of power.

On the drawing 0 andddenote'thebrakerails, 0 denotes the ramp-rail, and a and 6' denote reinforcing-girders for and of said rails c d e. 70 denotes triangular members I supported in pairs by transverse base-plates 1 and having each an oblique face 2', upon which the gripper g is shown in its braking position, in which its members and 'g are kept tread are lifted oif the rails for about 1 cm.

With wheels having the broadest tyres and the highest treads existing, the lifting height will increase to about 3 cm.

The base-plate Z is somewhat shift'able in its longitudinal direction and its movement is limited in bothdirections by angular abutment members. Fig. 2 showsthe base plate. in one of its two end-positlons, F 1g. 3 in the other. I The triangular members 70 have downwardly ,chrected extensmns an which are located between two parallel transverse girdersn a.

The grippers f and g are also located in the gap between these girders. There are shown in Fig. 1 three pairs of girders an, and there v I said wheels contact with the rails, the ramp rail 6 is loosened from the wheel tyre andare, therefore, also three pairs of grippers.

The. two members forming a pair are connected with one another by a bolt 0, the ends of which can slide vertically in a slot- 5 of two guide-members p, p secured to the bottom-faces of the said girders. The length of the slots 3 is such that there issutficient play for the bolt 0 to follow the vertical movements of the grippers when their position changes from that in Fig. 2 to that in Fig. '3,

and reversely, and this guiding insures the bolt 0 agalnst accidental cross movements.

When the brake is lifted but not yet loaded by the'car wheels, the bolt 0 rests on the lower part of its guide and accordingly the two gripperv arms occupy a somewhat lower POSl tion and the opening between the brake rails is then somewhat smaller as shown in Fig. 2.

VVhennow a car enters into the brake the wheels press the brake rails away from each other. Since the, gripper arms are firmly connected with each other at their under portion by means of the bolt 0, during pressing apart of the brake rails the bearing plates h provided on said gripper arms must slide upon the oblique faces icof the supports 70 mounted on the base plate Z, thus lifting the entire gripping device into the position as indicated in Fig. 2 and the ramp rail assumes such ahigh position, thatthe wheels are lifted from the track rails. The bolt 0 now does not rest any more in its guide and the vertical weight, effected by the wheels, results therein that'said wheels are clamped in accordance with the wedge'angle, formed by the supporting plates 2'.

When the car is sufiiciently braked, the

.brake is laid down to the position according -to Fig. 3.

During lowering of the brake the angle of the gripper arms will not be changed until the wheels have come in contact with the track rails. As soon, however, as

the braking operation ceases. The loaded grippers now descend further with the whole The members m/: appear in diifcrent positions in Figs. 2 and 3 because the base plate Z on which these parts are mounted is some what shiftable as above indicated. In opera tive condition of the brake, according to Fig. 2, the base plate Z will be maintained inthe position as shown by means of the car wheel. If, however, the brake is in inoperative condition, as shown in Fig. 3, the plate Z will be kept inits outermost left-hand position by means of a spring (not shown). The gripper-arm g is provided with an abutmentplate Vhen the brake-rails are being lifted below a car, no guide like 9 or g" is required, but if they are lifted without load, as

is the rule, the abutment members keep the brake-rails so much off the track-rail that the cars run securely into the brake.

' I claim: 7 1

A gripper-brake for railways, comprising, in combination: liftable brake-rails; grip persconsisting each of two members and having said brake-rails secured to them; a ramprail also secured to said grippers; members located laterally from the gripper arms and having each an oblique face adapted to serve as support for one of the gripper-arms; these latter being adapted to SllClG upon said oblique face and to be depressed by a car running over the brake; means carrying the 7 said lateral members, and transverse girders supporting said means; and meanspermit ting vertical movements of said grippers, sul stantially as set forth. i

In testimony whereof I aflix' my signature.

HEINRICH PGSENTRUP. 

